A Refined Space Vector PWM Signal Generation for Multilevel Inverters

A refined space vector modulation scheme for multilevel inverters, using only the instantaneous sampled reference signals is presented in this paper. The proposed space vector pulse width modulation technique does not require the sector information and look-up tables to select the appropriate switching vectors. The inverter leg switching times are directly obtained from the instantaneous sampled reference signal amplitudes and centers the switching times for the middle space vectors in a sampling time interval, as in the case of conventional space vector pulse width modulation. The simulation results are presented to a five-level inverter system for dual-fed induction motor drive. The dual-fed structure is realized by opening the neutral-point of the conventional squirrel cage induction motor. The five-level inversion is obtained by feeding the dual-fed induction motor with four-level inverter from one end and two-level inverter from the other end.